563.11.1

parsimoniousknotRéseaux et Communications

16 févr. 2014 (il y a 3 années et 3 mois)

65 vue(s)

563.11.1 ZigBee



Samuel Nelson


University of Illinois

Fall 2007

2

What is ZigBee?


A low data rate, low power specification


ZigBee Alliance is


“an association of companies working
together to enable reliable, cost
-
effective, low
-
power, wirelessly networked, monitoring and
control products based on an open global
standard.“


2

ZigBee Alliance Homepage

3

ZigBee’s Place

Data Rate (Mbps)

Range

ZigBee

802.15.4

15.4c

802.15.3

802.15.3c

WPAN

WLAN

WMAN

WWAN

WiFi

802.11

0.01

0.1

1

10

100

1000

Bluetooth

802.15.1

IEEE 802.22

WiMax

IEEE 802.16

IEEE 802.20

Heile, B.
Wireless Sensor and Control Networks (PPT)
, 2006

4

History of ZigBee


No adequate solution for:


Smart badges


Home Automation


Interactive toys


IEEE 802.15.4 task

group set out to design

a standard with:


Low data rate


Long battery life


Very low complexity


In 2003, a standard was
completed

IEEE 802.11.4
Website

5

History of ZigBee


October 2002


ZigBee Alliance is formed


December 2004


ZigBee 1.0 is released


Current releases


802.15.4 is 2006


ZigBee specification is 2007

6

Protocol Stack and Responsibility

Physical Radio (PHY)

Medium Access (MAC)

Application

NWK

App Support (APS)

SSP

Responsibility

ZDO

Protocol Stack

Craig, W.
ZigBee
, 2004.
Heile, B.
Wireless…


7

IEEE 802.15.4 PHY

Heile, B.
Wireless Sensor and Control Networks (PPT)
, 2006


Direct Sequence Spread Spectrum


Link quality measurements


Used by higher layers

8

IEEE 802.15.4 MAC


Two addressing modes


16 bit (~65,000 devices)


64 bit (lots of devices)


CSMA/CA


Allows for network beaconing


Wake up periodically, checking for a beacon


Power savings


Nodes can sleep between beacons


Nodes that don’t have to route or randomly
receive can sleep until needed

9

Network Layer


Devices


ZigBee Coordinator


Network Creator


ZigBee Router


Multi
-
hop Routing


ZigBee End Device


Very low power

Light switch (ZED)

Status: Sleep,
except when flipped

Light source (ZC or ZR)

Status: Always On

10

Network Topologies

ZigBee Coordinator

ZigBee Router

ZigBee End Device

Star

Mesh

Cluster Tree

Heile, B.
Wireless Sensor and Control Networks (PPT)
, 2006

11

Routing


Ad hoc On Demand Distance Vector
(AODV)


Used for mesh topologies


Cluster
-
Tree Algorithm


Form clusters of nodes that make a tree

Ergen, S.
ZigBee/802.15.4 Summary
, 2004

12

ZigBee Applications

TELECOM
SERVICES

m
-
commerce

info services

object interaction
(Internet of Things)

ZigBee

Wireless Control that

Simply Works

HOME
CONTROL


TV

VCR

DVD/CD

remote



security

HVAC

lighting control

access control

irrigation


PC &
PERIPHERALS

INDUSTRIAL

CONTROL


asset mgt

process
control

environmental

energy mgt


PERSONAL
HEALTH CARE

security

HVAC

AMR

lighting control

access

control


mouse

keyboard

joystick


patient
monitoring

fitness
monitoring


Heile, B.
Wireless Sensor and Control Networks (PPT)
, 2006

13

Application Profiles


Profiles regulate types of messages to and
from end points


Public Profiles


Interoperability


Vendor Profiles


Undergoes certificate testing


Shouldn’t interfere with other ZigBee networks

14

Example Profiles


Home Automation


Devices used:


Light switch


Lamp


Thermostat


Industrial Plant Monitoring


Devices used:


Pressure sensors


Cameras


Thermostat

Heile, B.
Wireless Sensor and Control Networks (PPT)
, 2006

15

Application Messages


Periodic


Use beaconing system


Ex) Meter systems


Intermittent


Beaconless or disconnected


Ex) Light switch


Repetitive low latency


Time slot allocations


Ex) Security system

16

ZigBee Security


ZigBee is touted as “highly secure”


Relies on centralized infrastructure


Coordinator acts as trust center


Types of keys:


Master key


Installed out
-
of
-
band


Network key


Shared by all devices


No protection against “insider” attacks


Link key


Derived from master key

17

Trust Center


Can be the coordinator or a dedicated
device on the network


Trust during Join


Authenticate join requests


Network


Updates and distributes network key


End
-
to
-
End Configuration


Assists link key setup

ZigBee Alliance,
ZigBee Security Specification Overview
, 2005

18

End
-
to
-
End Key Establishment

ZigBee Alliance,
ZigBee Security Specification Overview
, 2005

19

ZigBee vs. Bluetooth


Larger Range


100m vs. 10m


Lower Data Rate


20 to 250 Kbps vs. 1 Mbps


Lower Energy


Multi
-
year vs. multi
-
day battery life



Device numbers


7 slaves per network vs. 65,000 nodes

20

Conclusions


ZigBee is beneficial for low data rate, low
power applications


Control


Automation


Monitoring


Centralized trust center helps to manage
security

21

References


ZigBee Alliance home page:


http://www.zigbee.org/en/index.asp


ZigBee Alliance tutorial


http://www.zigbee.org/en/resources/presentati
ons.asp


IEEE 802.15.4 task group


http://www.ieee802.org/15/pub/TG4.html